Rubik’s cube is not just the quintessential hand-held puzzle, though: it’s also an iconic piece of design, so I co-opted it when making a new chest of drawers for my son’s room. This cubic piece of furniture has only one of the three required axes of rotation, so is unsolvable in the conventional sense, but can be arranged in any configuration you like by non-sporting means. The drawers do pose a brain-bending challenge: the first thing you have to solve is detecting that they’re there, and all three have hidden locks in different locations.